One dispenser for such sheets from such a stack is described in U.S. Pat. No. 4,416,392, assigned to the assignee of this application, wherein the stack of sheets is disposed in a box and the sheets can be withdrawn through a slot in the top of the box and centrally disposed parallel to the opposite edges of the sheets which are coated with the bands of adhesive. The box described in U.S. Pat. No. 4,416,392, however, provides no means for preventing the second sheet in the stack from being withdrawn with the first sheet in the stack in response to force applied to the first sheet to withdraw it. Thus, to separate the first sheet from the second after the first sheet is withdrawn from the box, the first sheet must be manually peeled from the second while manually holding the second sheet, which is inconvenient.
U.S. Pat. No. 4,416,392 also discloses a dispenser for such a stack of sheet material wherein a base is provided for supporting a removable cover within which is disposed the stack of sheet material. The cover is provided with an opening in its top wall and the stack of sheets are urged toward the top wall by a spring. The top wall is formed by two inclined portions which terminate at the dispensing opening. While the spring in this dispenser provides means for preventing the second sheet in the stack from being withdrawn with the first sheet in the stack in response to force applied to the first sheet to withdraw it due to the pressure the spring provides between the second sheet and the top wall, this dispenser comprises four basic parts to dispense the stack of sheets, and the sharp edges in the dispenser at the opening cause sheets that are dispensed to become stressed during the dispensing action about the edges of the opening so that the sheets retain a curl after they are dispensed.
U.S. Pat. No. 4,653,666, assigned to the assignee of this application, discloses a further embodiment of a dispenser for such a stack of sheets. This dispenser comprises a box which fits about the stack of sheets and has a centrally disposed opening transverse to the edges coated with the adhesive. A spring member in the box presses the stack of sheets toward the opening. Extending from the top wall of the box and into the opening are flexible polymeric flaps which during dispensing of the sheets bend to form convex arcuate surfaces about which the sheets are drawn as they are dispensed. This structure thus avoids the development of any curl in the dispensed sheets so that the sheets, after being dispensed and positioned on a receptor lay generally flat along the surface of the receptor and thus are not as subject to becoming dislodged as they would be had a curl been present in the dispensed sheet. This dispenser, as noted however, comprises a number of parts.
U.S. Pat. No. 4,796,781, also assigned to the assignee of this application, describes a refillable dispenser for such a stack of sheets comprising a base part adapted to be supported on a horizontal support surface and to support the stack of sheets; and a body part having a bottom surface including spaced pressure surface portions adapted to engage and be supported on the upper surface of the stack adjacent the edges of the sheets along which the narrow bands of adhesive are coated with the spaced pressure surface portions engaging an upper surface of the sheets at predetermined distances from the edges of the sheets along which the narrow bands of adhesive are coated, and convex arcuate surface portions between the pressure surface portions and a top surface of the body part defining a slot through and extending centrally across the body part. The convex arcuate surface portions have radii having a dimension at least as great as the predetermined distances to restrict curling of sheets of paper pulled from the dispenser through the slot, and the body part has sufficient weight (e.g., about 0.5 to 1.5 pound) to afford pulling a sheet from the stack through the slot without substantially lifting the body part from the stack.
While the dispensers described in U.S. Pat. Nos. 4,653,666 and 4,796,781 are effective in allowing sheets to be withdrawn from the stack without either curling or wrinkling the sheets and without withdrawing the second sheet in the stack with the sheet being withdrawn, they are too expensive and complex for use with a stack containing a small number of sheets such as persons might want to carry with them, such as in their pockets, briefcases or purses.